1. Field of the Invention
The present invention relates to a semiconductor package having a high-speed signal input/output terminal.
2. Description of the Related Art
Known as a conventional semiconductor package having a high-speed signal input/output terminal is a semiconductor package capable of transmitting a high-speed signal without degradation by mounting a connector on a part of the package. However, in such a semiconductor package having a connector mounted on a part of the package, a structure for mounting the connector is complicated to cause a cost increase. Further, it is difficult to make the package compact because of the necessity of mounting the connector.
Japanese Patent Laid-open No. 2000-232197 discloses a semiconductor package having a configuration such that a high-speed signal electrode is surrounded by a ground electrode. Owing to this configuration that the high-speed signal electrode is surrounded by the ground electrode, the inductance at a connecting portion for a high-speed signal can be reduced to thereby reduce the degradation of the high-speed signal. In the semiconductor package described in this publication, the inductance at the high-speed signal connecting portion can be reduced. However, it cannot be completely nullified, and signal degradation is caused in transmitting a high-frequency signal having a frequency of 20 GHz or more. The inductance at the connecting portion can be reduced also by reducing the ball diameter of a ball grid array (BGA) composed of solder balls. In this case, however, mechanical reliability is lowered in mounting the semiconductor package on a printed wiring board.